Correlation of pulmonary functions of COPD patients to those of their first-degree children.
(57/254)
OBJECTIVE: To assess the risk factors correlating to the likelihood for airflow obstruction among first-degree children of chronic obstructive pulmonary disease (COPD) patients and whether familial aggregation of pulmonary function abnormality exists. METHODS: Fifty-nine smokers with COPD and 28 smokers without COPD as control and all their children available were recruited into the study. Their history was recorded and a binary logistic regression analysis was carried out to ascertain the effects of their relationship to a proband with COPD, when other potential risk factors were controlled. RESULTS: Children with COPD probands showed increased risk of FEV1 below the 70% predicted (OR = 1.987) after accounting for the effects of smoking, sex and clinical symptoms. The lower the pulmonary function of the COPD proband, the higher the risk to their children for FEV1 below the 70% predicted. CONCLUSIONS: Our finding demonstrates the presence of a household aggregation inclination of COPD and pulmonary function impairment. Genetic factors might act as the basis of the familial aggregation. (+info)
A comparison of salmeterol with albuterol in the treatment of mild-to-moderate asthma.
(58/254)
BACKGROUND: An effective, long-acting bronchodilator could benefit patients with asthma who have symptoms not controlled by antiinflammatory drugs. We compared a new long-acting, inhaled beta 2-adrenoceptor agonist, salmeterol, with a short-acting beta 2-agonist, albuterol, in the treatment of mild-to-moderate asthma. METHODS: We randomly assigned 234 patients (150 male and 84 female patients 12 to 73 years old) to one of three treatment groups: one group received 42 micrograms of salmeterol twice daily, one received 180 micrograms of albuterol four times daily, and one received placebo. Treatment was assigned in a double-blind fashion, and all patients could use supplemental inhaled albuterol as needed during the 12-week treatment period. RESULTS: Measurements of the forced expiratory volume in one second, performed hourly for 12 consecutive hours, showed that a single dose of salmeterol produced a greater mean area under the curve than two doses of albuterol taken 6 hours apart (6.3 vs. 4.9 liter.hr, P < 0.05). The difference was significant on day 1 and at week 4 of the study, but not at week 8 or 12. Salmeterol was also more effective than albuterol or placebo (with albuterol taken as needed) in increasing the morning peak expiratory flow rate: salmeterol induced a mean increase of 24 liters per minute over the pretreatment values, as compared with a decrease of 6 liters per minute with albuterol (P < 0.001) and an increase of 1 liter per minute with placebo (P = 0.002). The mean overall symptom score was improved most by salmeterol treatment (P < 0.05), with the number of days with symptoms and of nights with awakenings decreasing by 22 percent and 52 percent, respectively; there were no differences in results between albuterol treatment and placebo administration. We found no evidence of tolerance to the bronchodilating effects of salmeterol, and adverse reactions to all the treatments were infrequent and mild. CONCLUSIONS: For the management of mild-to-moderate asthma, salmeterol given twice daily is superior to albuterol given either four times daily or as needed. (+info)
Effect of the second-generation antihistamine, fexofenadine, on cough reflex sensitivity and pulmonary function.
(59/254)
AIMS: Current guidelines recommend the use of first-generation antihistamines for the treatment of cough due to rhinitis/postnasal drip syndrome. The antitussive activity of the second-generation antihistamine, fexofenadine, has not been investigated. Therefore, we evaluated the effect of fexofenadine on capsaicin-induced cough in healthy volunteers and in subjects with acute viral upper respiratory tract infection (URI). METHODS: Twelve healthy volunteers and 12 subjects with URI underwent pulmonary function testing and capsaicin cough challenge on two separate days, 2 h after ingesting 180 mg fexofenadine or matched placebo. Subjects inhaled single, vital-capacity breaths of capsaicin aerosol, administered in incremental doubling concentrations, until the concentration inducing five or more coughs (C5) was determined. RESULTS: In both subject groups, C5 was not significantly different after fexofenadine compared to placebo. In subjects with URI, pulmonary function studies were also similar. In healthy volunteers, however, FEV1 and FEF(25-75), pulmonary function parameters reflecting the degree of airway dilatation, were significantly increased after fexofenadine. Mean (95% CI) values for FEV1(L) after fexofenadine and placebo were 3.16 (2.77, 3.55) and 3.08 (2.69, 3.47), respectively (P = 0.017). Mean values for FEF(25-75)(L/s) were 3.49 (3.10, 3.88) and 3.26 (2.79, 3.72), respectively (P = 0.029). CONCLUSIONS: Fexofenadine demonstrated no antitussive activity against capsaicin-induced cough in healthy volunteers and subjects with URI. The ineffectiveness of fexofenadine in suppressing cough probably reflects the lack of anticholinergic activity and central nervous system penetrance that is characteristic of first-generation antihistamines. The mild bronchodilation induced by fexofenadine in healthy volunteers is of unclear clinical significance and requires further investigation. (+info)
Ozone exposure decreases the effect of a deep inhalation on forced expiratory flow in normal subjects.
(60/254)
Sixteen healthy nonsmoking subjects (7 women), 21-49 yr old, were exposed in a climate chamber to either clean air or 300 parts/billion ozone on 4 days for 5 h each day. Before each exposure, the subjects had been pretreated with either oxidants (fish oil) or antioxidants (multivitamins). The study design was double-blind crossover with randomized allocation to the exposure regime. Full and partial flow-volume curves were recorded in the morning and before and during a histamine provocation at the end of the day. Nasal cavity volume and inflammatory markers in nasal lavage fluid were also measured. Compared with air, ozone exposure decreased peak expiratory flow, forced expiratory volume in 1 s, and forced vital capacity (FVC), with no significant effect from the pretreatment regimens. Ozone decreased the ratio of maximal to partial flow at 40% FVC by 0.08 +/- 0.03 (mean +/- SE, analysis of variance: P = 0.018) and at 30% FVC by 0.10 +/- 0.05 (P = 0.070). Ozone exposure did not significantly increase bronchial responsiveness, but, after treatment with fish oil, partial flows decreased more than after vitamins during the histamine test, without changing the maximal-to-partial flow ratio. The decreased effect of a deep inhalation after ozone exposure can be explained by changes in airway hysteresis relative to parenchymal hysteresis, due either to ozone-induced airway inflammation or to less deep inspiration after ozone, not significantly influenced by multivitamins or fish oil. (+info)
Genetic polymorphism of GSTM1 and antioxidant supplementation influence lung function in relation to ozone exposure in asthmatic children in Mexico City.
(61/254)
BACKGROUND: We recently reported that antioxidant supplementation with vitamins C and E mitigated ozone related decline in forced expiratory flow (FEF(25-75)) in 158 asthmatic children in an area with high ozone exposure in Mexico City. METHODS: A study was undertaken to determine whether deletion of glutathione S-transferase M1 (GSTM1 null genotype), a gene involved in response to oxidative stress, influences ozone related decline in FEF(25-75) and the benefit of antioxidant supplementation. RESULTS: GSTM1 null children receiving placebo had significant ozone related decrements in FEF(25-75) (percentage change per 50 ppb of ozone 2.9 (95% CI -5.2 to -0.6), p=0.01); GSTM1 positive children did not. Conversely, the effect of antioxidants was stronger in children with the GSTM1 null genotype. CONCLUSIONS: Asthmatic children with a genetic deficiency of GSTM1 may be more susceptible to the deleterious effects of ozone on the small airways and might derive greater benefit from antioxidant supplementation. (+info)
Detection of expiratory flow limitation in COPD using the forced oscillation technique.
(62/254)
Expiratory flow limitation (EFL) during tidal breathing is a major determinant of dynamic hyperinflation and exercise limitation in chronic obstructive pulmonary disease (COPD). Current methods of detecting this are either invasive or unsuited to following changes breath-by-breath. It was hypothesised that tidal flow limitation would substantially reduce the total respiratory system reactance (Xrs) during expiration, and that this reduction could be used to reliably detect if EFL was present. To test this, 5-Hz forced oscillations were applied at the mouth in seven healthy subjects and 15 COPD patients (mean +/- sD forced expiratory volume in one second was 36.8 +/- 11.5% predicted) during quiet breathing. COPD breaths were analysed (n=206) and classified as flow-limited if flow decreased as alveolar pressure increased, indeterminate if flow decreased at constant alveolar pressure, or nonflow-limited. Of these, 85 breaths were flow-limited, 80 were not and 41 were indeterminate. Among other indices, mean inspiratory minus mean expiratory Xrs (deltaXrs) and minimum expiratory Xrs (Xexp,min) identified flow-limited breaths with 100% specificity and sensitivity using a threshold between 2.53-3.12 cmH2O x s x L(-1) (deltaXrs) and -7.38- -6.76 cmH2O x s x L(-1) (Xexp,min) representing 6.0% and 3.9% of the total range of values respectively. No flow-limited breaths were seen in the normal subjects by either method. Within-breath respiratory system reactance provides an accurate, reliable and noninvasive technique to detect expiratory flow limitation in patients with chronic obstructive pulmonary disease. (+info)
Association between self-reported childhood socioeconomic position and adult lung function: findings from the British Women's Heart and Health Study.
(63/254)
BACKGROUND: A study was undertaken to assess the associations between indicators of early life socioeconomic position and lung function in older adulthood. METHODS: The associations of self-reported indicators of childhood socioeconomic position with adult lung function (forced expiratory volume in 1 second (FEV(1)), forced vital capacity (FVC), and forced expiratory flow rate during mid expiration (FEF(25-75)), all measured using standard procedures) were assessed in a cross sectional study of 3641 British women aged 60-79 years. RESULTS: In confounder adjusted analyses, each individual indicator of childhood circumstances was inversely associated with each measure of lung function. In the fully adjusted models (including mutual adjustment for each of the other indicators of childhood socioeconomic circumstances), only childhood occupational social class and access to a car were associated with lung function in adulthood. However, there were strong linear trends of worsening lung function with greater numbers of indicators of childhood poverty (all p values <0.001). CONCLUSIONS: Childhood poverty is associated with poorer lung function in women aged 60-79 years. Adverse childhood circumstances that affect both lung growth and development and cardiovascular disease in later life may explain some of the well known associations between poor lung function and cardiovascular disease, or lung function may be an important mediating factor in this association. (+info)
Pulmonary function of herdsmen.
(64/254)
OBJECTIVE: To determine whether the pulmonary function deficit documented previously in Fulani children is also present in adult Fulani herdsmen in northern Nigeria. SUBJECTS AND METHODS: The subjects for this study consisted of adult Fulani men from the hamlet of Magama Gumau and adult non-Fulani men from the city of Jos. Age, height, weight, mid-arm circumference (MAC), triceps skin-fold thickness, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory flow during the middle half of the FVC maneuver (FEF25-75%), and peak expiratory flow rate (PEF) were measured. Body mass index (BMI) and FEV1/FVC were calculated for all subjects. Multiple regression analysis was performed to identify correlations between pulmonary function parameters and anthropometric variables. RESULTS: The 44 Fulani subjects and 28 urban subjects were well-matched for age and height. The Fulani men weighed significantly less than the urban men (58.5+/-9.4 versus 67.4+/-11.3 kg, p <0.001) and consequently had significantly lower BMI, MAC, and triceps skin-fold thickness. The only significant difference in pulmonary function parameters between the two groups was in FEV1/FVC (0.93+/-0.1 versus 0.85+/-0.1, p <0.001). Small but significant correlations were found between pulmonary function parameters and anthropometric variables for both study populations. CONCLUSIONS: The pulmonary function deficits documented previously in Fulani children and adolescents were not present in adult Fulani men. However, the observed elevation in FEV1/FVC in the rural Fulani men as compared to their urban counterparts, which is often seen in restrictive pulmonary patterns, deserves further study. (+info)